Axial length decrease accompanying successful glaucoma filtration surgery

Permanent ocular remodeling in the setting of chronic hypotony after trabeculectomy: A case report

Purpose

Trabeculectomy surgery is a commonly performed procedure for treatment of glaucoma. While the goal is to lower intraocular pressure, over-filtration may cause hypotony with ocular structural changes and vision loss.

Observations

A 53-year-old woman with primary open-angle glaucoma was referred to our service for further evaluation. The patient previously underwent trabeculectomy 9 years prior and was found to have a cataract and hypotony maculopathy in the right eye. Treatment options included cataract surgery alone, bleb revision alone, or combined cataract extraction and bleb revision. Biometry revealed corneal astigmatism in the right eye, and significant disparity in axial length between the two eyes. Since the axial length and corneal astigmatic changes were presumed to be at least partially reversible, measurements from the non-operative left eye influenced the lens selection for the hypotonous right eye. The patient underwent combined phacoemulsification and bleb revision. While IOP increased and hypotony was partly reversed, there was hyperopic and astigmatic refractive surprise after surgery.The patient subsequently underwent intraocular lens exchange using biometric values of the previously hypotonous eye and met the target post-operative refractive goal.

Conclusions and importance

This case demonstrates changes to the axial length and ocular structure following longstanding hypotony maculopathy may be permanent, even after restoration of normotensive intraocular pressure.

Reversal of severe myopia by 24 years of hypotony with subsequent stable refraction after 2 years of normal intraocular pressure

Purpose

To report sustained axial length shortening and hyperopic shift (refraction changed from -8 to -2 diopters) induced by 24 years of profound IOP (intraocular pressure) reduction with subsequent refractive stability 2 years after IOP rose to 11-17 mm Hg.

Observations

A 25-year-old woman with elevated episcleral venous pressure glaucoma underwent non-penetrating trabeculectomy and subsequent laser goniopuncture in her left eye. She had chronically low IOP (1-12 mm Hg) for the next 24 years. Hypotony maculopathy was present in postoperative years 13-14 and 18-24 but resolved at age 49 when emesis-induced iris prolapse obstructed the filtering passage and transiently raised IOP to 40. Medical management and iridectomy with flap suturing stabilized IOP between 11 and 17 mm Hg.Refraction before OS trabeculectomy was OD -7.50/OS -9.00. In postoperative year 24 spherical equivalent phakic refraction was OD -9.00/OS -1.50. Biometry 1 year after resolution of hypotony showed axial lengths OD 24.8, OS 22.6 mm. Cataract surgery was performed in postoperative years 24/26 (OD/OS) with Tecnis DCBOO intraocular lenses of powers 14.0/21.5 diopters; postoperative refractions, 2 years after OS IOP rose to 11-17 mm Hg, were OD +0.25-0.50 x 015/OS -0.75-1.25 x 160 with 20/25 corrected acuity in each eye.Cardiovascular symptoms 24 years after the onset of her glaucoma led to a diagnosis of severe pulmonary hypertension.

Conclusions and importance

This case demonstrates that 2 decades of chronic IOP reduction can reverse myopia (by > 2 mm reduction in axial length) with subsequent refractive stability 2 years after IOP normalization. In addition, the case shows that ocular signs of pulmonary hypertension may precede cardiovascular signs by 2 decades.

Peripapillary Vascular Density in Childhood Glaucoma: A Pilot Comparative Study with Age and Sex Matched Healthy Subjects

PURPOSE

The aim of this study concerns the evaluation of peripapillary vessel indices in childhood glaucoma (CG) and healthy subjects.

MATERIAL AND METHODS

In this prospective, unicenter, observational cross-sectional study, patients with CG and age and sex-matched healthy subjects were included. We compared retinal nerve fiber layer (RNFL) measurements in optical coherence tomography (OCT), peripapillary vessel density (PVD), and the flux index (FI) of the superficial vascular plexus from OCT angiography (OCT-A) between CG patients and control groups.

RESULTS

We included 39 patients (68 eyes) with CG and 50 (95 eyes) healthy subjects. The peripapillary RNFL thickness, vessel density, and flux index were significantly lower in the CG group than in the control group. The mean PVD of CG patients was 0.52 ± 0.043%, compared with 0.55 ± 0.014%, p < 0.0001 in healthy subjects. The mean FI was 0.32 ± 0.054 versus 0.37 ± 0.028, p < 0.0001, in CG patients and healthy subjects, respectively. PVD and FI in the superior, inferior, and temporal sectors were significantly lower in CG. The peripapillary RNFL thickness showed a higher area under the ROC curve (AUROC) for discriminating healthy and CG eyes and was significantly different than the PVD (0.797, 95%CI 0.726-0.869; p < 0.0001 vs. 0.664, 95%CI 0.574-0.752; p 0.00037), p 0.012.

CONCLUSIONS

PVD and FI show lower values in CG and correlate with RNFL thickness measurement but have lower diagnostic ability than RNFL thickness measurement. Our results reveal possible differences in the pathogenesis of microvascular compromise in childhood glaucoma patients.

Factors Associated with Refractive Prediction Error after Phacotrabeculectomy

PURPOSE

To compare refractive prediction errors between phacotrabeculectomy and phacoemulsification.

METHODS

Refractive prediction error was defined as the difference in spherical equivalent between the predicted value using the Barrett Universal II formula and the actual value obtained at postoperative one month. Forty-eight eyes that had undergone phacotrabeculectomy (19 eyes, open-angle glaucoma; 29 eyes, angle-closure glaucoma) were matched with 48 eyes that had undergone phacoemulsification by age, average keratometry value and axial length (AL), and their prediction errors were compared. The factors associated with prediction errors were analyzed by multivariable regression analyses.

RESULTS

The phacotrabeculectomy group showed a larger absolute prediction error than the phacoemulsification group (0.51 ± 0.37 Diopters vs. 0.38 ± 0.22 Diopters, p = 0.033). Larger absolute prediction error was associated with longer AL (p = 0.010) and higher intraocular pressure (IOP) difference (p = 0.012). Hyperopic shift (prediction error > 0) was associated with shallower preoperative anterior chamber depth (ACD) (p = 0.024) and larger IOP difference (p = 0.031). In the phacotrabeculectomy group, the prediction error was inversely correlated with AL: long eyes showed myopic shift and short eyes hyperopic shift (p = 0.002).

CONCLUSIONS

Surgeons should be aware of the possibility of worse refractive outcomes when planning phacotrabeculectomy, especially in eyes with high preoperative IOP, shallow ACD, and/or extreme AL.

Premium Intraocular Lenses in Glaucoma-A Systematic Review

The incidence of both cataract and glaucoma is increasing globally. With increasing patient expectation and improved technology, premium intraocular lenses (IOLs), including presbyopia-correcting and toric IOLs, are being increasingly implanted today. However, concerns remain regarding the use of premium IOLs, particularly presbyopia-correcting IOLs, in eyes with glaucoma. This systematic review evaluates the use of premium IOLs in glaucoma. A comprehensive search of the MEDLINE database was performed from inception until 1 June 2023. Initial search yielded 1404 records, of which 12 were included in the final review of post-operative outcomes. Studies demonstrated high spectacle independence for distance and good patient satisfaction in glaucomatous eyes, with positive outcomes also in post-operative visual acuity, residual astigmatism, and contrast sensitivity. Considerations in patient selection include anatomical and functional factors, such as the type and severity of glaucomatous visual field defects, glaucoma subtype, presence of ocular surface disease, ocular changes after glaucoma surgery, and the reliability of disease monitoring, all of which may be affected by, or influence, the outcomes of premium IOL implantation in glaucoma patients. Regular reviews on this topic are needed in order to keep up with the rapid advancements in IOL technology and glaucoma surgical treatments.

Neuroretinal Rim Response to Transient Intraocular Pressure Challenge Predicts the Extent of Retinal Ganglion Cell Loss in Experimental Glaucoma

Purpose

To determine if the optic nerve head (ONH) response to transient elevated intraocular pressure (IOP) can predict the extent of neural loss in the nonhuman primate experimental glaucoma model.

Methods

The anterior chamber pressure of 21 healthy animals (5.4 ± 1.2 years, 8 female) was adjusted to 25 mm Hg for two hours followed by 10 mm Hg for an additional two hours. For the duration of IOP challenge the ONH was imaged using radial optical coherence tomography (OCT) scans at five-minute intervals. Afterward, a randomized sample of 14 of these subjects had unilateral experimental glaucoma induced and were monitored with OCT imaging, tonometry, and ocular biometry at two-week intervals.

Results

With pressure challenge, the maximum decrease in ONH minimum rim width (MRW) was 40 ± 10.5 µm at 25 mm Hg and was correlated with the precannulation MRW, Bruch's membrane opening (BMO) position, and the anterior lamina cribrosa surface position (P = 0.01). The maximum return of MRW at 10 mm Hg was 16.1 ± 5.0 µm and was not associated with any precannulation ONH feature (P = 0.24). However, healthy eyes with greater thickness return at 10 mm Hg had greater loss of MRW and retinal nerve fiber layer (RNFL) at a cumulative IOP of 1000 mm Hg · days after induction of experimental glaucoma. In addition, MRW and RNFL thinning was correlated with an increase in axial length (P < 0.01).

Conclusion

This study's findings suggest that the ONH's response to transient changes in IOP are associated with features of the ONH and surrounding tissues. The neural rim properties at baseline and the extent of axial elongation are associated with the severity of glaucomatous loss in the nonhuman primate model.

Refractive Outcomes for Combined Phacoemulsification and Glaucoma Drainage Procedure

INTRODUCTION

To evaluate the refractive outcome of combined cataract extraction and glaucoma drainage device (GDD) surgery.

METHODS

Patients who had undergone combined phacoemulsification with GDD surgery [Baerveldt, Abbott Medical, Abbott Park (IL) or Ahmed valve, New World Medical, Rancho Cucamonga (CA)] between June 2009 and August 2017 were included in the study. The main outcome measure evaluated was whether or not spherical equivalent (SE) between ± 1D from target refraction was achieved at 3-6 months postoperatively.

RESULTS

The final analysis included 42 eyes of 38 patients who underwent combined phacoemulsification and GDD surgery. A refractive outcome of spherical equivalent (SE) between ± 1D of the target refraction was achieved in 30 of 42 eyes (71.43%) at 3-6 months after surgery. Mean preoperative axial length (AL) of eyes with postoperative SE outside ± 1D from target (SD = 0.98, p = 0.003) was noted to be 25.37 ± 0.98 mm (longer mean AL) and that of eyes with SE between ± 1D (SD = 0.89, p = 0.000) was found to be 23.34 ± 0.89 mm (average mean AL). Twelve (29%) eyes were noted to have a mean 0.52D (SD = 0.49; range 0.02-1.49) of corneal astigmatism induced by combined surgery. Age, central corneal thickness, preoperative anterior chamber depth, and pre- and postoperative intraocular pressure did not significantly affect refractive outcomes.

CONCLUSION

Refractive outcomes within 1.00D of the target refraction were achieved in most patients undergoing a combined surgical approach. Longer AL was a risk factor among patients with refractive change > 1.00D from target.

Accuracy of different lens power calculation formulas in patients with phacomorphic glaucoma

PURPOSE:

The purpose of the study was to determine the most accurate formula for intraocular lens (IOL) power calculation among five currently used formulas in eyes with phacomorphic glaucoma (PG) undergoing cataract extraction surgery.

MATERIALS AND METHODS:

In this prospective interventional case series Patients diagnosed with PG were undergone uneventful phacoemulsification and IOL implantation. After 3 months, the refractive outcome for each formula was evaluated with mean prediction error (PE), mean absolute error (MAE), and the percentages of eyes within 0.25 D and 0.5 D of predicted error.

RESULTS:

Twenty-three patients completed the study. PEs were significantly different among the 5 formulas (P = 0.019), and Holladay I had the least error (−0.02 ± 1.11). Haigis formula had the highest hyperopic shift (0.37 ± 1.22), highest MAE (0.99 ± 0.78) and the lowest percentages of desired PEs, while the SRK II produced the greatest percentages. The overall differences in MAE between the 5 formulas were statistically insignificant (P = 0.547).

CONCLUSION:

In some extreme situations like patients with PG, lower generation of IOL power calculation formulas may still produce more acceptable refractive outcomes.

How a dynamic optical system maintains image quality: Self-adjustment of the human eye

The eyeball is continually subjected to forces that cause alterations to its shape and dimensions, as well as to its optical components. Forces that induce accommodation result in an intentional change in focus; others, such as the effect of intraocular pressure fluctuations, are more subtle. Although the mechanical properties of the eyeball and its components permit mediation of such subtle forces, the concomitant optical changes are not detected by the visual system. Optical self-adjustment is postulated as the mechanism that maintains image quality. The purpose of this study was to investigate how self-adjustment occurs by using an optical model of the eyeball and to test the requisite optical and biometric conditions.

Bleb Compressive Sutures in the Management of Hypotony Maculopathy after Glaucoma Surgery

PURPOSE

The aim of the study was to assess the efficacy and safety of compressive sutures in patients with hypotony maculopathy after glaucoma surgery.

METHODS

This retrospective case series analyzes the clinical outcomes of conjunctival compressive sutures in 17 patients with hypotony maculopathy developed after glaucoma surgery. Compressive Nylon 10-0 single sutures were used in all patients; in two patients, the procedure was repeated. All patients underwent ophthalmic evaluation and macular OCT scanning before the surgery, one month, six months, and one year after the procedure.

RESULTS

Mean intraocular pressure (IOP) before suturing was 2.3 ± 1.57 mmHg and increased to 14.2 ± 7.03 mmHg (p = 0.00065) one month after the procedure. After six months, mean IOP was 10.2 ± 4.3 mmHg (p = 0.005), and after one year ± 4.7 mmHg (p = 0.0117). To obtain the target pressure, the sutures had to be removed in one patient, and medical therapy was undertaken in three patients. Mean decimal best-corrected visual acuity (BCVA) before the sutures was 0.18 ± 0.13 and increased to 0.53 ± 0.25 (p = 0.0004) after one month, to 0.46 ± 0.31 (p = 0.005) after six months, and to 0.31 ± 0.22 (p = 0.025) after one year. In one case, leakage from the bleb was observed after the procedure and bleb revision was required.

CONCLUSIONS

transconjuctival compressive sutures seem to be an efficient and safe technique for managing hypotony maculopathy after glaucoma surgery.

Topical Review: Causes of Refractive Error After Silicone-oil Removal Combined with Cataract Surgery

SIGNIFICANCE

This review summarizes the main factors of refractive error after silicone oil removal combined with cataract surgery.The post-operative refractive results of silicone oil removal combined with cataract surgery are closely related to the patient's future vision quality. This report summarizes the factors that influence the difference between the actual post-operative refractive power and the pre-operatively predicted refractive power after silicone oil removal combined with cataract surgery, including axial length, anterior chamber depth, silicone oil, commonly used tools for measuring intraocular lens power, and intraocular lens power calculation formulas, among others. The aim of the report is to assist clinical and scientific research on the elimination of refractive error after silicone oil removal combined with cataract surgery.

Long-term outcomes of prediction error after combined phacoemulsification and trabeculectomy in glaucoma patients

Background

To investigate long-term outcomes of prediction error after phacotrabeculectomy and to determine risk factors that may cause unstable prediction error after phacotrabeculectomy in glaucoma patients.

Methods

A total 120 eyes of 120 patients who had underwent uncomplicated phacotrabeculectomy (combined group) or phacoemulsification (phaco-only group) were included. Best-corrected visual acuity (BCVA), intraocular pressure (IOP) were measured before and after surgery, and anterior segment parameters including anterior chamber depth (ACD), lens vault (LV), and anterior vault (AV) measured using anterior-segment optical coherence tomography were compared between the two groups. The mean absolute error (MAE) at 3, 6, 12, and 24 months postoperatively were compared. Risk factors associated with unstable prediction error (MAE ≥ 0.5) were investigated in the combined group.

Results

In both groups, BCVA was improved and IOP was decreased significantly. MAE at 3, 6, 12, 24 months postoperatively were not significantly different between two groups. The risk factors for unstable prediction error after 12 months of phacotrabeculectomy were old age and LV. Whereas, the only factor predicting unstable prediction error after 24 months of phacotrabeculectomy was LV. The cut-off value of LV for predicting unstable refractive error analyzed by the ROC curve was 0.855 mm.

Conclusions

Phacotrabeculectomy may be an effective treatment with stable long-term outcomes of prediction error similar to phacoemulsification in patients with glaucoma. However, elderly patients or patients with large LV may be predisposed to unstable prediction error after phacotrabeculectomy.

Phacotrabeculectomy versus Phaco with Implantation of the Ex-PRESS Device: Surgical and Refractive Outcomes-A Randomized Controlled Trial

The aim of this study was to compare surgical and refractive outcomes between phacotrabeculectomy (P-Trab) and phaco with Ex-PRESS (P-Ex-PRESS) for glaucoma at a 6-month follow-up. This prospective randomized controlled trial included 81 eyes; 43 eyes (53%) and 38 eyes (47%) were assigned to the P-Ex-PRESS and P-Trab groups, respectively. Refraction, intraocular pressure (IOP), and best-corrected visual acuity were measured. Refractive change was analyzed using the cylinder’s magnitude, and polar analysis assessed the change in the trend of astigmatism [with-the-rule, against-the-rule (ATR), oblique (OBL)], evaluating mean astigmatism in centroid form. All patients showed a statistically significant postoperative decrease in IOP (P < 0.05). There were no differences between the groups in terms of postoperative IOP and visual outcomes or in astigmatism preoperatively or postoperatively (P = 0.61, P = 0.74). In both groups, the mean preoperative and postoperative astigmatism were ATR and OBL, respectively. Preoperative and postoperative centroids in the P-Ex-PRESS group were 0.44 ± 1.32 D at 177° and 0.35 ± 1 D at 8°, respectively, (P = 0.5) and in the P-Trab group were 0.16 ± 1.5 D at 141° and 0.39 ± 1.38 D at 29°, respectively (P = 0.38). Both P-Ex-PRESS and P-Trab showed comparable antihypertensive efficacy in treating open-angle glaucoma over 6 months. Preoperative and postoperative astigmatism did not differ between groups. The groups showed comparable results for final visual acuity.

Refractive outcomes of cataract surgery in patients receiving trabeculectomy-a comparative study of combined and sequential approaches

BACKGROUND

Cataract surgery in combination with or after trabeculectomy is often required for improving vision in glaucoma patients. Intraocular pressure (IOP) changes may influence refractive outcomes after cataract surgery. We compared refractive outcomes of the combined and sequential approaches in managing glaucoma and cataract.

METHODS

This retrospective case-control study included 52 patients (57 eyes) who underwent phacotrabeculectomy (combined group) and 39 patients (42 eyes) who underwent phacoemulsification at least three months post-trabeculectomy (sequential group). The IOP and refraction prediction error were compared at three months after cataract surgery. Univariate regression analyses were used to assess risk factors for the postoperative refraction prediction error.

RESULTS

Anti-glaucomatous medications were not administered to either group. The mean postoperative IOP (12.96 vs. 13.80 mmHg; P = .392), refraction prediction error (-0.32 ± 1.53 vs. -0.47 ± 1.14 D, P = .594), mean absolute error (1.02 ± 1.18 vs. 0.8 ± 0.93 D, P = .320), and surgically induced astigmatism (1.85 ± 1.40 vs. 2.16 ± 1.16 D, P = .161) did not differ significantly between the combined and sequential groups. In the sequential group, the refraction prediction error correlated to the IOP change, with a 1-mm Hg rise resulting in a -0.07-diopter shift between the expected and observed refraction (r = -0.380, R² = 0.144, P = .013); no such correlation was observed in the combined group.

CONCLUSION

Both approaches resulted in similar effective IOP control and accurate intraocular lens predictability. The IOP change affected the postoperative refraction prediction error only in the sequential approach.

Prospective cohort study of risk factors for choroidal detachment after trabeculectomy

PURPOSE

To investigate risk factors for choroidal detachment after trabeculectomy.

METHODS

We prospectively evaluated 97 patients with open-angle glaucoma who underwent primary trabeculectomy to investigate risk factors for choroidal detachment after trabeculectomy. The primary outcome measure was risk factors for the occurrence and severity of choroidal detachment after trabeculectomy. Choroidal detachment severity was quantified as the number of fundus quadrants with choroidal detachment.

RESULTS

Sixteen patients (16.5%) had choroidal detachment. Mean period between surgery and occurrence of choroidal detachment was 7.9 ± 5.7 days. Mean intraocular pressure (IOP) on the first day of choroidal detachment was 6.1 ± 3.0 mm Hg. Multivariable analyses revealed that the exfoliation glaucoma, greater ΔIOP between preoperative and lowest postoperative IOPs, and thicker cornea were associated with choroidal detachment (P = 0.022, P = 0.002, and P = 0.013, respectively). These factors were also associated with the severity of choroidal detachment (exfoliation glaucoma; P = 0.013, greater ΔIOP; P < 0.001, and thicker cornea; P = 0.006).

CONCLUSIONS

Exfoliation glaucoma, more IOP reduction, and thicker cornea are associated with the occurrence and severity of choroidal detachment after trabeculectomy.

Ocular and Systemic Diurnal Rhythms in Emmetropic and Myopic Adults

Purpose

To investigate ocular and systemic diurnal rhythms in emmetropic and myopic adults and examine relationships with light exposure.

Methods

Adult subjects (n = 42, 22–41 years) underwent measurements every 4 hours for 24 hours, including blood pressure, heart rate, body temperature, intraocular pressure (IOP), ocular biometry, and optical coherence tomography imaging. Mean ocular perfusion pressure (MOPP) was calculated. Saliva was collected for melatonin and cortisol analysis. Acrophase and amplitude for each parameter were compared between refractive error groups. Subjects wore a light, sleep, and activity monitor for 1 week before measurements.

Results

All parameters exhibited significant diurnal rhythm (ANOVA, P < 0.05 for all). Choroidal thickness peaked at 2.42 hours, with a diurnal variation of 25.8 ± 13.44 μm. Axial length peaked at 12.96 hours, with a variation of 35.71 ± 6.6 μm. Melatonin peaked at 3.19 hours during the dark period, while cortisol peaked after light onset at 8.86 hours. IOP peaked at 11.24 hours, with a variation of 4.92 ± 1.57 mm Hg, in antiphase with MOPP, which peaked at 22.02 hours. Amplitudes of daily variations were not correlated with light exposure, and rhythms were not significantly different between emmetropes and myopes, except for body temperature and MOPP.

Conclusions

Diurnal variations in ocular and systemic parameters were observed in young adults; however, these variations were not associated with habitual light exposure. Emmetropic and myopic refractive error groups showed small but significant differences in body temperature and MOPP, while other ocular and systemic patterns were similar.

Twenty-four hour ocular and systemic diurnal rhythms in children

PURPOSE

Ocular diurnal rhythms have been implicated in myopia, glaucoma, diabetes, and other ocular pathologies. Ocular rhythms have been well described in adults; however, they have not yet been fully examined in children. The goal of this study was to investigate ocular and systemic diurnal rhythms over 24 h in children.

METHODS

Subjects, ages 5 to 14 years (n = 18), wore a light, sleep, and activity monitor for one week to assess habitual sleep/wake patterns, then underwent diurnal measurements every 4 h for 24 h. Measurements included blood pressure, heart rate, body temperature, intraocular pressure (IOP), ocular biometry, and optical coherence tomography imaging. Saliva was collected for melatonin and cortisol analysis. Mean ocular perfusion pressure was calculated from IOP and blood pressure. Central corneal thickness, corneal power, anterior chamber depth, lens thickness, vitreous chamber depth, and axial length were determined from biometry. Total retinal thickness, retinal pigment epithelium (RPE) + photoreceptor outer segment thickness, photoreceptor inner segment thickness, and choroidal thickness were determined for a 1 mm diameter centred on the fovea. Subjects' amplitude and acrophase of diurnal variation for each parameter were determined using Fourier analysis, and mean acrophase was calculated using unit vector averaging.

RESULTS

Repeated measures analysis of variance (ANOVA) showed that all parameters except anterior chamber depth exhibited significant variations over 24 h (p ≤ 0.005 for all). Axial length underwent diurnal variation of 45.25 ± 6.30 μm with an acrophase at 12.92 h, and choroidal thickness underwent diurnal variation of 26.25 ± 2.67 μm with an acrophase at 1.90 h. IOP was approximately in phase with axial length, with a diurnal variation of 4.19 ± 0.50 mmHg and acrophase at 11.37 h. Total retinal thickness underwent a significant diurnal variation of 4.09 ± 0.39 μm with an acrophase at 15.04 h. The RPE + outer segment layer was thickest at 3.25 h, while the inner segment layer was thickest at 14.95 h. Melatonin peaked during the dark period at 2.36 h, and cortisol peaked after light onset at 9.22 h.

CONCLUSIONS

Ocular and systemic diurnal rhythms were robust in children and similar to those previously reported in adult populations. Axial length and IOP were approximately in phase with each other, and in antiphase to choroidal thickness. These findings may have important implications in myopia development in children.

Refractive outcomes of cataract surgery in primary congenital glaucoma

AIM

To evaluate refractive outcomes of cataract surgery with intraocular lens (IOL) implantation in operated eyes of primary congenital glaucoma (PCG).

DESIGN

A retrospective case-control study.

METHODS

Patients of PCG who developed cataract following trabeculectomy with trabeculotomy were recruited. Preoperative biometry was recorded and refractive outcomes of the patients in terms of spherical equivalent (SE) and prediction error were noted at 3 and at 12 months following surgery. The refractive outcomes were compared with non-glaucomatous eyes of children in similar age group who underwent lens aspiration with IOL implantation (controls).

RESULTS

The median age of the children with PCG (n = 31) at the time of cataract surgery was 60 months, similar to controls (n = 29); 48 months (p = 0.3). The SE in PCG eyes at 12 months was comparable to controls (p = 0.18). The prediction error (postoperative SE - predicted SE) at 3 months (p = 0.018) and at 12 months (p = 0.03) among PCG eyes was higher and more myopic compared with controls. The range of prediction error at 12 months in PCG eyes was - 8.6 to + 5.8 D (median - 2.0 D), whereas in controls it was - 4.2 to + 6.3 D (median + 0.5 D). For each mmHg intraocular pressure (IOP) increase there was 0.42 mm increase in axial length among PCG eyes and a 0.24 mm increase among controls (p < 0.001).

CONCLUSIONS

After IOL implantation there was a greater prediction error and a greater myopic shift among PCG eyes. Eyes of children with PCG are more prone to refractive surprises as their axial length changes are more sensitive to IOP fluctuation.

Significant hyperopic shift in a patient with extreme myopia following severe hypotonia caused by glaucoma filtering surgery

INTRODUCTION:

To report the case of a high hyperopic refractive shift associated with significant shortening of the ocular axial length following glaucoma filtering surgery.

METHODS:

Case report. Patient's records were consulted retrospectively.

RESULTS:

A 57-year-old woman, highly myopic, with a history of bilateral intraocular refractive surgery in 1998 (phakic lens ZB5M) and bilensectomy in 2011 (phakic intraocular lens extraction plus cataract surgery with pseudophakic intraocular lens implantation), presented with consistently high intraocular pressure. Despite the treatment with different topical antiglaucomatous medications and good compliance, her intraocular pressure values remained consistently above 20 mmHg. In 2016, the patient was submitted for glaucoma filtering surgery and the mini shunt Ex-Press was implanted in both the eyes (3 months between surgeries). On the first postoperative day, the eyes were hypotonic (intraocular pressure of 5 mmHg) and bilateral macular edema was observed. Three days later, the intraocular pressure in both the eyes reached values higher than 6 mmHg (between 6 and 14 mmHg). Five months after the surgery the macular edema resolved and a significant shortening of the axial length and an important hyperopic refractive shift was observed. When comparing the preoperative and postoperative (18 months) measurements, the variation of the axial length was 2.49 mm in the right eye and 2.19 mm in the left eye; the patient refraction (spherical equivalent) shifted 2.50 diopters in the right eye and 1.75 diopters in the left eye.

CONCLUSION:

To the best of our knowledge, we report herein the first documented case of an axial length change of this magnitude after glaucoma filtering surgery.

Effect of Cycloplegia on Optical Biometry in Pediatric Eyes

PURPOSE

To study the effect of cycloplegia on optical biometry parameters in pediatric eyes using the Lenstar LS 900 (Haag-Streit, Koeniz, Switzerland).

METHODS

In this observational and comparative study, 56 normal eyes and 20 cataractous eyes in children between 5 and 15 years of age were included. Measurements were taken before and after cycloplegia using 2% homatropine drops. Parameters studied were axial length, central corneal thickness, keratometry, anterior chamber depth, and lens thickness. The Wilcoxon test was used to compare the effects of cycloplegia on all parameters.

RESULTS

Cycloplegia resulted in a statistically significant decrease in axial length (P < .05), central corneal thickness (P < .05), and lens thickness (P < .001) and an increase in the anterior chamber depth (P < .001) in normal eyes. In the cataract group, cycloplegia resulted in an increase in anterior chamber depth (P < .001) and decrease in lens thickness (P < .001).

CONCLUSIONS

Biometry measurements have to be carefully interpreted in pediatric eyes where cycloplegia is an important part of the examination. [J Pediatr Ophthalmol Strabismus. 2018;55(4):260-265.].

Changes in choroidal thickness following trabeculectomy and its correlation with the decline in intraocular pressure

PURPOSE

Evaluate whether there are significant changes in choroidal thickness following trabeculectomy, and how they relate do the decline in intraocular pressure.

METHODS

This was a prospective evaluation of 28 eyes who underwent Moorfields modified trabeculectomy. The choroidal thickness was measured via OCT with enhanced depth imaging, before surgery and 1 day, 1 week and 1 month after surgery. Measurements were taken at the fovea, 1000 µm temporal to the fovea and 1000 µm nasal to the fovea. The relationship between choroidal thickness and intraocular pressure was statistically evaluated.

RESULTS

The mean intraocular pressure before surgery was 25.07 ± 4.64 mmHg; 8.57 ± 3.62 mmHg after 1 day; 10.36 ± 4.39 mmHg after 1 week and 13.71 ± 5.13 mmHg after 1 month. Mean choroidal thickness increased after trabeculectomy with maximal values at 1 week. The largest increase was found at the fovea, with an average before surgery of 253.54 ± 62.01 µm; 286.75 ± 64.20 µm at 1 day, 286.36 ± 63.14 µm at 1 week and 271.00 ± 60.31 µm at 1 month. Increase in choroidal thickness was significant 1 day and 1 week after surgery in the foveal (p = 0.012, p = 0.007) and temporal (p = 0.040, p = 0.000) locations and 1 week postoperatively on the nasal location (p = 0.016). None of them were significant at 1 month after surgery. Preoperative IOP and choroidal thickness were correlated at all macular locations (ρ = 0.449-0.525, p = 0.004-0.016) yet no correlation was found between increase in choroidal thickness and decline in intraocular pressure in the postoperative period.

CONCLUSION

Choroidal thickness appears to increase temporarily after trabeculectomy and these changes were not correlated with the decline in intraocular pressure. Further research is required to fully understand this phenomenon.

Excessive scleral shrinkage, rather than choroidal thickening, is a major contributor to the development of hypotony maculopathy after trabeculectomy

Purpose

We previously reported that eyes with hypotony maculopathy (HM) after trabeculectomy (TLE) exhibited more reduction of axial length (AL) than those without HM, suggesting that inward collapse of the scleral wall may contribute to the development of HM after TLE. However, we did not evaluate change in choroidal thickness (CT), which could influence AL measures. We compared the magnitude and rate of AL and CT changes in eyes with and without HM by simultaneously measuring these parameters before and after TLE.

Methods

We enrolled 77 eyes of 77consecutive patients with glaucoma, who underwent TLE between March 2014 and March 2016. Intraocular pressure (IOP), central corneal thickness, keratometry, AL, and CT were measured pre- and postoperatively, up to 6 months. These biometrics were compared in eyes with and without HM.

Results

The 14 patients who developed HM were significantly younger than those who did not. The eyes with HM exhibited significantly reduced AL (2.8%) compared to those without HM (0.7%). There was no significant difference in CT change between the two groups. The rate of AL reduction was significantly correlated with age, postoperative IOP, and preoperative AL. Post-adjustment logistic regression analysis revealed that eyes with AL reduction rate ≥ 2% had 11.67 higher risk for developing HM (95% confidence interval, 1.28–106.6; P = 0.03).

Conclusions

AL reduction rates ≥ 2% were significantly associated with HM. Excessive reduction in AL, which was seen in eyes with HM, was not an artificial measure resulting from choroidal thickening but rather reflected reductions in the anterior-posterior diameter of the eyeball. Inward collapse of the scleral wall leads to redundancy of the chorioretinal tissue, contributing to the development of HM after TLE.

Late-onset Hypotony Maculopathy After Trabeculectomy in a Highly Myopic Patient With Juvenile Open-angle Glaucoma

Hypotony maculopathy is a sight-threatening complication after trabeculectomy. We report on a 34-year-old man with juvenile open-angle glaucoma and high myopia, who developed hypotony maculopathy 14 years after trabeculectomy without bleb leak. This represents the longest known period from trabeculectomy to the development of hypotony maculopathy without bleb leak. The possible mechanisms for the development of late-onset hypotony maculopathy in the highly myopic patient are progressive scleral thinning, reduced scleral rigidity, and scleral morphologic change with aging. These changes might weaken the biomechanical properties of sclera and then contribute to the collapse of the scleral wall during hypotony. This case serves as a reminder that hypotony maculopathy can happen up to 14 years after tabeculectomy even without bleb leak and hypotony should be avoided after trabeculectomy in highly myopic patients with juvenile open-angle glaucoma.

Combined Approach to Phacoemulsification and Trabeculectomy Results in Less Ideal Refractive Outcomes Compared With the Sequential Approach

PURPOSE

To compare the refractive outcomes of combined versus sequential trabeculectomy and then phacoemulsification.

METHODS

We compared eyes that underwent uncomplicated combined phacotrabeculectomy (combined group, 87 eyes), phacoemulsification at least 3 months after trabeculectomy (sequential group, 56 eyes), and phacoemulsification only (control group, 78 eyes) between January 1, 2006 and January 1, 2014. The main outcome measure was refractive prediction error (RPE)-defined as postoperative subjective spherical equivalent refraction minus predicted spherical equivalent refraction.

RESULTS

The study population was predominantly Chinese and the mean age at their cataract surgery was 67.2±9.59 years. Compared with controls, RPE (-0.40±0.70 vs. -0.01±0.50, P<0.001) and mean absolute error (0.62±0.50 vs. 0.39±0.31, P=0.003) were greater for the combined group but not for the sequential group. Proportionately fewer patients in the combined group achieved final subjective refraction within ±0.5D (27.6% vs. 46.2%, P=0.01) compared with controls. Within the sequential group, there were no differences in RPE when the fellow eye axial length was used to predict refractive outcome (P=0.17) or between the group with precataract surgery IOPs of ≤11 mm Hg (-0.28±0.82) and the group with >11 mm Hg (-0.28±0.53, P=0.99). For the sequential group, the use of contact A scan yielded less RPE compared with IOLMaster (P=0.01).

CONCLUSIONS

Combined approach to trabeculectomy and phacoemulsification resulted in greater myopic RPEs that were expectedly greater than those found in the phacoemulsification group.

Visual acuity and corneal higher-order aberrations after EX-PRESS or trabeculectomy, and the determination of associated factors that influence visual function

PURPOSE

This study investigated postoperative visual acuity and corneal higher-order aberrations following EX-PRESS or trabeculectomy.

METHODS

Out of 56 eyes of 56 patients analyzed, 30 eyes were treated using trabeculectomy, while 26 eyes were treated with EX-PRESS. Visual acuity and corneal higher-order aberrations were analyzed in both groups before and at 2 weeks, 1, 2, and 3 months after the surgeries. Risk factors that could potentially influence corneal higher-order aberrations were evaluated.

RESULTS

Significant reductions in the IOP were observed at 3 months after the surgery in both groups. Although a significant decrease in the visual acuity (logMAR) was observed at 2 weeks after the surgery in both groups, at 1 month after the surgeries, there were no significant differences found for the vision as compared to the baseline. At each study visit in the trabeculectomy group, significantly higher corneal higher-order aberrations compared to baseline were noted. In the EX-PRESS group, however, these aberrations were no longer significantly different from the baseline at month 2 (P = 0.36). Analysis of the risk factors indicated that hypotony could influence corneal higher-order aberrations after surgery.

CONCLUSIONS

Corneal higher-order aberrations were significantly increased at 1 month after EX-PRESS treatment, with levels returning to baseline by 2 months. After trabeculectomy, however, corneal higher-order aberrations remained significantly increased at 3 months after the procedure.

Changes in anterior ocular structures and macula following deep sclerectomy with collagen implant

PURPOSE

To determine the effect of intraocular pressure (IOP) lowering with deep sclerectomy (DS) on visual acuity, macular structures, and anterior ocular dimensions during the early postoperative period.

METHODS

We prospectively analyzed 35 eyes of 35 patients scheduled for DS. Our focus with the measurements was on early postoperative changes in anterior ocular and macular structures related to IOP lowering during the first month after DS. In addition to a clinical ophthalmologic examination, our measurements included corneal topography, measurement of ocular dimensions with optical biometry, and examination of macular structure with optical coherence tomography. These measurements were repeated 1, 2, and 4 weeks postoperatively.

RESULTS

Best-corrected visual acuity (BCVA) decreased 1 week postoperatively to 0.22 (0.20) LogMAR (p = 0.006). The BCVA then increased to its preoperative level, 0.17 (0.18) (p = 0.28), after 4 weeks. Axial length decreased from 24.12 (1.81) mm to 24.04 (1.81) (p<0.001) 4 weeks postoperatively. The steeper meridian of corneal curvature and average corneal power increased postoperatively; central corneal thickness was decreased. No significant change appeared in other measurements.

CONCLUSIONS

We found changes in corneal curvature and ocular dimensions after DS. These changes were relatively small and do not completely explain the decrease in visual acuity postoperatively. Macular structures showed no changes.

Changes in macular thickness after trabeculectomy with or without adjunctive 5-fluorouracil

Conflict of interest.

None of the authors have any conflict of interest to declare, financial or otherwise. No financial or other support was received for the study.

Background.

The aim of the study was to assess changes in macular thickness after trabeculectomy in respect to the use of 5-fluorouracil (5-FU) as well as to analyse possible associations between the postoperative changes in macular thickness and intraocular pressure (IOP).

Materials and methods.

The prospective observational study included 106 eyes (100 patients) with glaucoma who underwent trabeculectomy with or without 5-FU. Subsequently 5-FU needling was performed if failure of the filtrating bleb occurred. Macular thickness and the IOP were evaluated before, one week, and six months after the surgery. The mean and sectoral macular thickness was assessed using spectral domain optical coherence tomography.

Results.

The mean (±SD) IOP reduced from 27.71 (±6.88) mmHg at baseline to 18.3 (±8.1) mmHg one week (p < 0.001) and 15.1 (±7.6) mmHg six months (p < 0.001) after trabeculectomy. One week postoperatively, the mean macular thickness increased from 285.19 (±15.98) μm to 288.9 (±16.31) μm (p < 0.001); macular thickening was significant in all subfields (p < 0.001) and correlated positively with IOP reduction (rho = 0.312, p = 0.001 for central subfield). After six months, macula remained thicker only at the central and inner nasal subfields (p < 0.05). The changes in macular thickness were not affected by the use of 5-fluorouracil.

Conclusions.

Trabeculectomy may induce a slight macular thickening which is more pronounced in the early postoperative period. The IOP reduction plays an important role in this process and is associated with thicker postoperative macula. However, the use of adjunctive 5-FU has no influence on macular thickness after glaucoma surgery despite its potential hypotonic, inflammatory and cytotoxic effects.

Intraocular Pressure, Axial Length, and Refractive Changes after Phacoemulsification and Trabeculectomy for Open-Angle Glaucoma

PURPOSE

To compare changes in intraocular pressure (IOP), axial eye length (AEL), and refractive outcome in primary open-angle glaucoma patients undergoing cataract surgery and trabeculectomy in dependence of the sequence of surgeries.

MATERIALS AND METHODS

We retrospectively analysed 48 eyes. The changes in refraction, intraocular pressure, and axial eye length were analysed after surgery. In group A (21 subjects), phacoemulsification was performed before trabeculectomy, and in group B (27 subjects), trabeculectomy was performed before phacoemulsification with a minimum time span between interventions of 6 months.

RESULTS

The reduction in IOP and the decrease in AEL after trabeculectomy were significant after 6 and 12 months postsurgery (p < 0.001 each). The decrease in AEL was 0.42 ± 0.11% at 6 months after surgery and 0.40 ± 0.13% after 12 months from surgery; this decrease in AEL was comparable between the groups. The refractive outcome was significantly different between the groups (group A: 0.35 ± 0.75 dpt, group B: -0.05 ± 0.36 dpt, p = 0.018); in group A, trabeculectomy caused a hyperopic shift of 0.34 ± 0.44 dpt (p = 0.002) at 12 months postsurgery.

CONCLUSION

IOP reduction after trabeculectomy causes AEL shortening. The effect on refractive outcome depends on the sequence of surgeries. Better refractive outcome is achieved if phacoemulsification is performed after trabeculectomy.

Vision-related quality of life following glaucoma filtration surgery

BACKGROUND

To evaluate vision-related quality of life (VR-QOL) following glaucoma filtration surgery.

METHODS

A total of 103 glaucoma patients scheduled to undergo glaucoma filtration surgery. Prior to and at three months after glaucoma filtration surgery, trabeculectomy or EX-PRESS, all patients completed the 25-item National Eye Institute Visual Function Questionnaire (VFQ-25). A total of 48 patients underwent combined cataract and filtration surgery. The clinical data collected pre- and postoperatively included best-corrected visual acuity (BCVA) and intraocular pressure (IOP).

RESULTS

The IOP decreased significantly from 19.0 ± 8.1 mmHg to 9.7 ± 3.9 mmHg (P < 0.001). Preoperative VFQ-25 composite score (65.8 ± 15.6) was similar to the postoperative score (67.8 ± 16.6). A significantly improved VFQ-25 composite score (pre: 63.2 ± 17.1, post: 67.7 ± 17.8; P = 0.001) was observed in the patients who underwent combined cataract and filtration surgery. There was a significant association between the BCVA changes in the operated eye and the changes in the VFQ-25 composite score (r = -0.315, P = 0.003).

CONCLUSIONS

Although glaucoma filtration surgery by itself did not decrease the VR-QOL in glaucoma patients, there was significant improvement in the VR-QOL after the patients underwent combined cataract and glaucoma filtration surgery.

Refractive Outcome of Cataract Surgery in Eyes With Prior Trabeculectomy: Risk Factors for Postoperative Myopia

PURPOSE

To examine refractive outcomes after phacoemulsification in eyes with prior trabeculectomy.

DESIGN

Retrospective observational case-control study METHODS:: Comparison of eyes of glaucoma patients undergoing cataract surgery after trabeculectomy (study group) with a matched group with medically controlled glaucoma (control group). Laser interferometry was used to obtain ocular biometry. We measured the difference between the expected and actual postoperative refraction using third-generation and fourth-generation intraocular lens (IOL) prediction formulae (Haigis, Holladay 2, Hoffer Q, and SRK-T). A residual difference of >1.0 D of hyperopia or myopia was considered a "refractive surprise."

RESULTS

In total, 86 eyes (85 patients) were included, including 23 eyes (22 patients) in the study group and 63 eyes (63 patients) in the control group. The mean follow-up was 12.2±4.1 months. Eyes (n=13) with trabeculectomy and a preoperative intraocular pressure (IOP)≤9 mm Hg had significantly more large myopic surprises than the control group for all IOL formulae (P=0.015 Haigis, P=0.003 Holladay 2, P=0.004 Hoffer Q, P=0.003 SRK-T). Eyes (n=10) with trabeculectomy and preoperative IOP>9 mm Hg, however, did not have significantly more myopic errors than the control (P>0.05, all formulae). An "IOP spike" defined as a >50% rise in IOP from baseline within 1 month of cataract surgery in the subgroup with preoperative IOP≤9 mm Hg (n=8) was associated with increased risk of large myopic surprise (3/8 subset vs. 1/63 control eyes for all formulae; P=0.004 Haigis, P=0.004 Holladay 2, P=0.001 Hoffer Q, P=0.004 SRK-T) as well as for large myopic and hyperopic surprises overall (4/8 subset vs. ≤2/63 depending upon formulae; all P≤0.001).

CONCLUSIONS

Low posttrabeculectomy IOP (≤9 mm Hg) is a risk factor for significant myopic surprise when undergoing subsequent cataract surgery despite using laser interferometry to measure ocular biometry and later generation formulae to determine IOL power. In addition, an IOP spike was associated with a 50% risk for large refractive surprise in this low IOP group.

Ocular Biometric Changes after Trabeculectomy

This review article aimed to evaluate ocular biometric changes after trabeculectomy. The PubMed database was searched using the keywords "axial length" (AL), "anterior chamber depth" (ACD), "corneal astigmatism," "corneal topography" and "trabeculectomy." The extracted studies were categorized based on the evaluated parameters and the biometry method (contact and non-contact). Comparable studies with respect to their sample size were combined for statistical analysis. Twenty-five studies including 690 individuals which met the inclusion criteria were selected. After trabeculectomy, a significant and persistent AL reduction, with a range of 0.1-0.19 and 0.1-0.9 mm measured with contact and non-contact methods, respectively, was observed. With respect to topographic changes, 0.38-1.4 diopters (D) with-the-rule (WTR) astigmatism was induced postoperatively. All studies revealed ACD reduction immediately after surgery, which gradually deepened and approximated its preoperative levels on day 14. ACD reduction was not significant after that period in the majority of cases. In conclusion, changes in ACD is of small amount and of short period, thus it can be ignored; however, reported changes in AL and keratometry are of sufficient magnitude and can affect the refractive prediction of combined cataract surgery and trabeculectomy.

Changes in choroidal thickness after intraocular pressure reduction following trabeculectomy

PURPOSE

To evaluate the changes of peripapillary and subfoveal choroidal thickness (CT) after trabeculectomy.

METHODS

Prospective longitudinal study included 37 eyes with open-angle glaucoma. The subfoveal and peripapillary CT was measured using enhanced depth imaging spectral domain optical coherence tomography before trabeculectomy and 1 week, 3 and 6 months postoperatively. The associations between changes in the CT, intraocular pressure (IOP) and axial length were analysed.

RESULTS

The medium subfoveal CT (IQR) increased from 182 (97) μm at baseline to 267 (107) μm 1 week, 213 (97) μm 3 months and 207 (91) μm 6 months postoperatively (p < 0.001). The peripapillary CT increased in all four quadrants at all follow-ups (p < 0.05). The subfoveal and peripapillary choroidal thickening correlated with the magnitude of IOP reduction (p < 0.05) and axial length shortening (p < 0.01) during whole follow-up period. There was a peripapillary CT increase of 2.9 μm per mmHg of IOP reduction (p < 0.001, CI 1.5-4.4) and 4.8 μm per mm of baseline axial length (p = 0.049, CI 0.03-9.6) 1 week postoperatively after adjustment for baseline IOP. Six months postoperatively, the decrease in axial length was the only factor associated with peripapillary choroidal thickening (p = 0.031; regression coefficient: 73.29 μm/mm, CI 7.1-139.5).

CONCLUSION

Intraocular pressure (IOP) reduction after trabeculectomy caused the increase in subfoveal and peripapillary CT for at least 6 months postoperatively correlating with greater IOP reduction and axial length shortening. In the long term, the decrease in axial eye length, but not IOP, was the only factor to be associated with peripapillary choroidal thickening.

Changes in Axial Length and Refractive Error After Noninvasive Normalization of Intraocular Pressure From Elevated Levels

PURPOSE

To explore the changes in axial length and refractive error after noninvasive normalization of intraocular pressure (IOP) from elevated levels.

DESIGN

A prospective observational study.

METHODS

We enrolled 51 consecutive patients with abnormally elevated unilateral IOP (≥10 mm Hg compared with that of the fellow eye, in which the IOP was ≤21 mm Hg). In all patients, the keratometric value and axial length were obtained with the aid of an IOLMaster before and after IOP normalization (defined as attainment of an IOP difference of ≤3 mm Hg compared with the fellow eye, with or without topical application of ocular hypotensive therapy). We focused principally on IOP, axial length, the keratometric value, and the predicted refractive difference (the predicted refractive error after IOP normalization upon placement of an IOL with a power for emmetropia correction determined prior to IOP normalization).

RESULTS

The axial length was significantly reduced from 23.5 to 23.3 mm after IOP normalization, from 45.9 mm Hg to 14.3 mm Hg (P < .001). The change in IOP correlated with that of the axial length (r = 0.826, P < .001), but not with the change in the keratometric value (P = .618). The change in axial length per 10 mm Hg IOP decrease was -0.06 mm (P < .001). The IOP change was correlated with the predicted refractive difference (r = 0.693, P < .001); the predicted refractive difference per 10 mm Hg IOP decrease was +0.15 diopter (P < .001).

CONCLUSIONS

The axial length decreased and the predicted refractive difference increased (hyperopia) as IOP decreased. Therefore, a possible risk of postoperative hyperopic shift should be considered when biometric examination for IOL power calculation is performed in a patient with an abnormally elevated IOP.

Effect of trabeculectomy on the accuracy of intraocular lens calculations in patients with open-angle glaucoma

BACKGROUND

The objective of the study is to examine the effect of trabeculectomy on intraocular lens power calculations in patients with open-angle glaucoma (OAG) undergoing cataract surgery.

DESIGN

The design is retrospective data analysis.

PARTICIPANTS

There are a total of 55 eyes of 55 patients with OAG who had a cataract surgery alone or in combination with trabeculectomy.

METHODS

We classified OAG subjects into the following groups based on surgical history: only cataract surgery (OC group), cataract surgery after prior trabeculectomy (CAT group), and cataract surgery performed in combination with trabeculectomy (CCT group).

MAIN OUTCOME MEASURES

Differences between actual and predicted postoperative refractive error.

RESULTS

Mean error (ME, difference between postoperative and predicted SE) in the CCT group was significantly lower (towards myopia) than that of the OC group (P = 0.008). Additionally, mean absolute error (MAE, absolute value of ME) in the CAT group was significantly greater than in the OC group (P = 0.006). Using linear mixed models, the ME calculated with the SRK II formula was more accurate than the ME predicted by the SRK T formula in the CAT (P = 0.032) and CCT (P = 0.035) groups.

CONCLUSIONS

The intraocular lens power prediction accuracy was lower in the CAT and CCT groups than in the OC group. The prediction error was greater in the CAT group than in the OC group, and the direction of the prediction error tended to be towards myopia in the CCT group. The SRK II formula may be more accurate in predicting residual refractive error in the CAT and CCT groups.

Comparison of 1-Site and 2-Site Phacotrabeculectomy in the Small Adult Eyes With Concomitant Cataract and Glaucoma

The aim of this study was to compare the outcomes after phacotrabeculectomy at 1 or 2 sites in the small adult eyes with concomitant cataract and glaucoma.Patients who had 1-site (n = 26) or 2-site (n = 14) phacotrabeculectomy over a 4-year period at an eye surgery center were included. Eighteen eyes of 18 patients with glaucoma using any 1 prostaglandin analogue (latanoprost, travoprost, or bimatoprost) were compared with 8 normal control patients. The records of patients were reviewed, and intraocular pressure, best-corrected visual acuity, axial length, anterior chamber depth, corneal endothelial cell (CEC) density, Diopter were measured. The outcome was compared with postoperative and preoperative measurements for 3-month follow-ups.The follow-up time was 3 months. There was no difference between the operations in improving best-corrected visual acuity, lowering intraocular pressure, shortening axial length, and deepening anterior chamber depth. However, 2-site surgery was associated with significantly more CEC loss and refractive error. Postoperative complications were not different between the 2 groups.The CEC loss and the refractive error in 2-site group were higher than that of 1-site group. One-site surgery seems to cause less CEC damage and refractive error than the 2-site operation during the follow-up time of 3 months.

Effect of endoscopic cyclophotocoagulation on refractive outcomes when combined with cataract surgery

OBJECTIVE

To determine the difference between predicted and actual refractive outcomes after combined endoscopic cyclophotocoagulation and cataract surgery (phaco-ECP) in patients with open-angle glaucoma (OAG).

DESIGN

Retrospective case-control study of patients with OAG who underwent phaco-ECP compared with cataract surgery alone.

PARTICIPANTS

Eighty-three patients with OAG, aged 55 to 91 years, who underwent a combined phaco-ECP procedure and 58 biometry- and age-matched control patients with OAG who underwent cataract surgery alone.

METHODS

Patient records were retrospectively reviewed at the Department of Ophthalmology and Visual Sciences, Washington University School of Medicine in St. Louis (St. Louis, Mo.). The primary outcome was the difference in predicted and actual refractive outcomes in patients undergoing either phaco-ECP or standard cataract surgery.

RESULTS

Compared with phaco alone, the difference in predicted versus actual postoperative results was more myopic in the phaco-ECP group (0.029, -0.110, and -0.095 vs -0.169, -0.325, and -0.312 [p < 0.05] for Sanders, Retzlaff, Kraff/Theoretical, Hoffer Q, and Holladay, respectively). Moreover, the F test for variability showed significantly more variability in refractive outcomes in the phaco-ECP group compared with standard cataract surgery.

CONCLUSIONS

Patients undergoing phaco-ECP may have postoperative refractive errors that may vary from that predicted preoperatively more so than in cataract surgery alone. Surgeons may consider analyzing their results to determine whether any adjustment should be made to lens power selection when performing phaco-ECP.

Biometric Changes After Trabeculectomy with Contact and Non-contact Biometry

PURPOSE

To compare biometric changes measured with contact and noncontact methods after mitomycin-C-augmented trabeculectomy.

METHODS

In this prospective study, 31 eyes from 31 glaucoma patients scheduled for primary trabeculectomy were enrolled. Biometric parameters including axial length (AL), anterior chamber depth (ACD), and lens thickness (LT) were measured using contact ultrasound biometry (UD-6000 Ultrasonic A/B scanner biometer; Tomey Corporation, Nagoya, Japan) and a noncontact optical biometry device (Lenstar; Haag-Streit AG, Koeniz, Switzerland). Measurements were taken the day before trabeculectomy and then compared with measurements obtained 3 and 6 months after surgery.

RESULTS

The AL and ACD were significantly decreased at 3 and 6 months compared with baseline values taken with each biometry method. There was a significant increase in LT measured by the Lenstar device at the 3- and 6-month follow-up. At both the 3- and 6-month follow-up, the mean AL measurement reduction with the Lenstar device was significantly lower than that of the A-scan ultrasound measurements. The mean ACD changes between the two devices were not significantly different.

CONCLUSIONS

There is a small but significant decrease in the AL and ACD after trabeculectomy as measured with both the contact and noncontact methods. The amount of AL reduction measured is significantly smaller using the noncontact method, making it the preferable method for intraocular lens power calculation for patients who need cataract surgery combined with or after trabeculectomy. The LT measured by the Lenstar device increased significantly after the operation, which can be an early sign of the progression of cataractous changes after trabeculectomy.

Comparison of visual recovery following ex-PRESS versus trabeculectomy: results of a prospective randomized controlled trial

PURPOSE

To compare the rate of visual recovery after Ex-PRESS implantation versus standard trabeculectomy.

PATIENTS AND METHODS

Subjects enrolled in a prospective randomized controlled trial comparing Ex-PRESS to trabeculectomy were analyzed for postoperative changes in visual acuity (VA). Risk factors for visual loss (split fixation, cup-disc ratio, intraocular pressure, visual field mean deviation, and hypotony) were evaluated.

RESULTS

Sixty-four subjects were enrolled (33 Ex-PRESS, 31 trabeculectomy). There was no significant difference in mean logMAR VA between groups at baseline or any study visit. VA was significantly reduced up to week 2 following surgery in both the groups. However, by month 1, VA in the Ex-PRESS group was no longer significantly different from baseline (P=0.23) and remained nonsignificant at subsequent visits up to 6 months. In the trabeculectomy group, VA remained significantly lower than baseline at each study visit. At 6 months, 47% of the trabeculectomy eyes compared with 16% of the Ex-PRESS eyes had lost ≥2 Snellen lines (P=0.01). Reasons for VA loss included cataract, central retinal vein occlusion, and diabetic retinopathy, however, in a significant number of cases no cause could be determined. None of the risk factors evaluated were associated with vision loss.

CONCLUSIONS

Although there was no difference in mean VA between the Ex-PRESS and trabeculectomy groups at any time point, trabeculectomy eyes were more likely to lose ≥2 Snellen lines. In addition, VA recovered faster in the Ex-PRESS group.

Refractive outcomes of combined cataract and glaucoma surgery

PURPOSE

This study was designed to evaluate the refractive outcomes of combined cataract extraction and glaucoma surgery.

DESIGN

Retrospective case series.

METHODS

A retrospective chart review of patients undergoing simultaneous cataract extraction with trabeculectomy or glaucoma drainage device surgery was performed. The main outcome measure evaluated was whether or not spherical equivalent of -1.00 to +0.50 D was achieved at 3 to 6 months postoperatively. Secondary outcomes included: reduction in intraocular pressure, amount of cylinder induced by combined surgery, and individual patient characteristics that may have affected refractive outcome. Outcomes were compared with an age-matched and sex-matched control group of patients who had uncomplicated cataract surgery during the same time period.

RESULTS

Forty-three eyes of 36 patients underwent combined cataract extraction and glaucoma surgery. A refractive outcome of spherical equivalent between -1.00 and +0.50 D was achieved in 32 of 43 eyes (74%) at 3 to 6 months after surgery. Logistic regression analysis found a 1.14 increased risk of the refraction being outside this defined refractive range in older compared with younger patients (by year, 95% CI, 1.04-1.27). Type of lens implant used, type of glaucoma surgery, and preoperative best-corrected visual acuity did not significantly affect refractive outcome. In a subset of 22 eyes with available preoperative keratometry measures, a mean 1.31 D (SD=0.86; range, 0.26 to 3.76) of corneal astigmatism was induced by combined surgery. In comparison, a matched control group who had cataract surgery alone achieved target refractive outcome in 34 of 40 eyes (85%, P=0.001) and had a trend for less induced cylinder (0.99, SD=0.72, P=0.11).

CONCLUSIONS

Favorable refractive outcomes were achieved in the majority of patients despite the potential alteration of preoperative measurements and introduction of error into lens selection when using a combined approach. There does not seem to be a difference in the refractive outcome with regard to the type of glaucoma surgery performed. Control patients who had cataract surgery alone had a higher percentage of achieving target refractive goal and less induced cylinder.

Comparison of surgical outcomes after phacotrabeculectomy in primary angle-closure glaucoma versus primary open-angle glaucoma

Purpose:

To compare postoperative outcomes and assess factors associated with intraocular pressure (IOP) reduction after phacotrabeculectomy in patients with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG).

Methods:

This is a retrospective study of patients who underwent phacotrabeculectomy between 2010 and 2013. Factors including age, gender, visual field (VF), the number of glaucoma medications used, biometric changes, IOP, and surgical success rates were compared between groups.

Results:

There were 27 PACG and 34 POAG patients. The PACG group had a greater mean IOP reduction after phacotrabeculectomy compared to the POAG group (5.5 ± 7.9 mmHg versus 2.0 ± 4.2 mmHg; p = 0.03). However, the final mean IOP was similar between the two groups (PACG: 12.2 ± 4.8 mmHg, POAG: 12.3 ± 3.1 mmHg; p = 0.92). Phacotrabeculectomy resulted in a mean decrease in axial length (AL) of 0.16 ± 0.15 mm in PACG and 0.16 ± 0.11 mm in POAG (p = 0.96), and an increase in anterior chamber depth (ACD) of 1.41 ± 0.91 mm in PACG, and 0.87 ± 0.86 mm in POAG (p = 0.04). At 2 years follow-up, the cumulative success rate of phacotrabeculectomy was 74% in PACG and 62% in POAG. Multivariate analysis found that early glaucoma stage, greater postoperative increase in ACD, and high preoperative IOP were factors associated with greater IOP reduction.

Conclusion:

Postoperative success rates and mean IOP on the final visit after phacotrabeculectomy were similar between the PACG and POAG groups. Factors associated with IOP reduction were greater postoperative increase in ACD, and high preoperative IOP.

Intraocular Lens Power Changes after Mitomycin Trabeculectomy

Purpose

To evaluate biometric changes after mitomycin C augmented trabeculectomy and their effect on intraocular lens (IOL) power calculation using different formulas.

Methods

In this prospective, interventional case series study, 34 eyes of 31 phakic glaucoma patients who were scheduled for primary trabeculectomy were enrolled. Using a noncontact biometry device (Lenstar, Haag-Streit AG, Koeniz, Switzerland), axial length (AL), mean corneal power, and IOL power were calculated with the Hoffer Q, Holladay, and SRK/T formulas 1 day before surgery and compared to those obtained 3 and 6 months after the operation. Bland-Altman plot was used to determine agreement between preoperative and postoperative IOL power values.

Results

The AL was significantly decreased at month 3 (-0.14 ± 0.13 mm) and month 6 (-0.14 ± 0.15 mm) as compared to baseline values (both p values <0.001). Mean corneal power increased significantly at month 3 (0.41 ± 0.46 D; p<0.001) and month 6 (0.27 ± 0.47 D; p = 0.008). Using different formulas, IOL power did not change significantly after the operation (all ps≥0.17). The IOL power changes using the Hoffer Q formula were −0.09 ± 0.76 (p = 0.505) and 0.14 ± 0.9 D (p = 0.442) at 3 and 6 months, respectively; corresponding values were −0.1 ± 0.75 (p = 0.427) and 0.16 ± 0.79 D (p = 0.319) for Holladay and 0.01 ± 0.64 (p = 0.895) and 0.2 ± 0.71 D (p = 0.17) employing the SRK/T formula.

Conclusions

Despite significant changes in AL and corneal power after trabeculectomy, IOL power calculation remains unchanged; therefore adjustment of IOL power calculation after trabeculectomy seems unnecessary.

The short-term effects of exercise on intraocular pressure, choroidal thickness and axial length

Purpose

To explore ocular changes in healthy people after exercise.

Methods

Twenty five volunteers underwent exercise for 15 minutes on a treadmill. Measurements of choroidal thickness, intraocular pressure (IOP), ocular biometry, and blood pressure were taken before and after exercise. Enhanced Depth Imaging optical coherence tomography (EDI-OCT) was used to measure choroidal thickness at the fovea. Intraocular pressure (IOP) was measured by Goldmann applanation tonometry. Ocular biometric measures were collected using A scan ultrasound. Blood pressure was measured concurrently with the acquisition of the scans.

Results

Twenty five volunteers (25 eyes) with a mean age of 25.44±3.25 years were measured. There was a significant increase in systolic and diastolic pressure after exercise (P<0.05). The IOP showed a significant decrease after exercise (P<0.05). However there was no significant difference in the mean choroidal thickness, ocular axial length, anterior chamber depth, lens thickness, or vitreous length before and after exercise measurements (P>0.05).

Conclusion

There was a significant decrease in IOP from exercise without a change in choroidal thickness and ocular biometric measures. IOP and choroidal thickness were not correlated, suggesting that the IOP decrease from exercise is not due to changes in choridal thickness.

Axial biometry of the entire eye using ultra-long scan depth optical coherence tomography

PURPOSE

To assess the repeatability of axial biometry of the entire eye using ultra-long scan depth optical coherence tomography (OCT) and to investigate the agreement with IOLMaster measurements (Carl Zeiss Meditec).

DESIGN

Prospective, observational case series.

METHODS

There were 37 adult subjects enrolled in group 1 and 12 adult subjects enrolled in group 2. Using ultra-long scan depth OCT, the left eyes of these groups were measured in 2 separate sessions. The images were processed by a manual method and custom-developed automatic software. A model eye was imaged for verification. The subjects in group 2 were imaged using ultra-long scan depth OCT and using the IOLMaster for axial length measurement comparison.

RESULTS

All measured parameters of the model eye matched the geometric parameters. In group 1, there were no significant differences in all measured parameters using automatic and manual segmentation methods (P > .05, paired t test). The percentage of coefficient of repeatability of segments ranged from 0.3% to 3.9%. The corresponding interclass correlation coefficients ranged from 0.946 to 0.999. The correlation between the results using automatic and manual segmentation methods appeared to be strong (R(2) = 0.999; P < .05). In group 2, the axial length of the eye measured by the IOLMaster matched the results obtained by ultra-long scan depth OCT with the automatic method (R1(2) = 0.987; P < .05) and the manual method (R2(2) = 0.988; P < .05).

CONCLUSIONS

Automatic axial biometry using ultra-long scan depth OCT successfully measured each segment of the entire eye with good repeatability. With further development of automatic segmentation, ultra-long scan depth OCT seems to be a promising tool in the axial biometry of the entire eye.

Changes in axial length and choroidal thickness after intraocular pressure reduction resulting from trabeculectomy

Purpose

To evaluate changes in axial length and choroidal thickness after trabeculectomy.

Patients and methods

Fourteen patients under 80 years of age with glaucoma, were enrolled. The choroid was imaged using prototypical high-penetration optic coherence tomography (OCT) and the thickness was measured. Axial length, choroidal thickness, and intraocular pressure (IOP) were measured bilaterally at 3 pm 1 day before and 6 days after trabeculectomy. The choroidal thickness was measured at the fovea and four other locations (2 mm superior, temporal, inferior, and nasal to the center of the optic nerve head).

Results

The IOP and axial length significantly decreased in eyes that underwent trabeculectomy (P < 0.0001 for the IOP; P < 0.001 for axial length comparisons). The mean choroidal thicknesses significantly increased in eyes that underwent trabeculectomy compared to preoperatively (P < 0.0001 for the fovea; P < 0.01 for four locations around the optic disc). The mean magnitude of change in IOP was correlated positively with the mean magnitude of change in axial length, but not correlated with the mean magnitude of change in choroidal thickness at the fovea that underwent trabeculectomy. The sum of the axial length and subfoveal choroidal thickness in eyes decreased significantly postoperatively (P < 0.05).

Conclusion

The axial length shortened, the choroid thickened, and the sum of the axial length and subfoveal choroidal thickness decreased with IOP reduction early after trabeculectomy.

Changes in choroidal thickness, axial length, and ocular perfusion pressure accompanying successful glaucoma filtration surgery

PURPOSE

To investigate the changes in choroidal thickness (CT), axial length (AL), and ocular perfusion pressure (OPP) accompanying intraocular pressure (IOP) reduction after trabeculectomy. methods: Thirty-nine eyes of 39 patients with primary open-angle glaucoma uncontrolled by medical therapy were included in this prospective and interventional study. All patients underwent a fornix-based trabeculectomy. The CT was measured by enhanced depth imaging-optical coherence tomography. IOP, AL, and systolic/diastolic blood pressure were also measured, and OPP was calculated. All measurements were performed at baseline and 1 month after surgery.

RESULTS

The mean IOP was 25.0 ± 5.8 mm Hg at baseline and 11.7 ± 2.6 mm Hg after trabeculectomy (P<0.001), and the mean subfoveal CT was 295 ± 84 mm Hg at baseline and 331 ± 82 mm Hg after trabeculectomy (P<0.001). The mean AL was 23.64 ± 0.98 mm at baseline and 23.54 ± 0.96 mm after trabeculectomy (P<0.001), whereas the mean OPP was 38.8 ± 6.2 mm Hg preoperatively, and 51.1 ± 7.3 mm Hg postoperatively (P<0.001). The change in CT negatively correlated with the change in IOP (r=-0.785, P<0.001) and AL (r=-0.693, P<0.001), whereas it positively correlated with the change in OPP (r=0.418, P=0.008).

CONCLUSION

These results suggest that the large IOP decrease following trabeculectomy causes choroidal thickening. In addition, CT changes are associated with IOP and AL reduction as well as OPP increase.